In recent years, in order to achieve high breakdown voltage, low loss, and utilization of semiconductor devices, such as a MOSFET (Metal Oxide Semiconductor Field Effect Transistor), under a high temperature environment, silicon carbide has begun to be adopted as a material for a semiconductor device. Silicon carbide is a wide band gap semiconductor having a band gap larger than that of silicon, which has been conventionally widely used as a material for semiconductor devices. Hence, by adopting silicon carbide as a material for a semiconductor device, the semiconductor device can have a high breakdown voltage, reduced on resistance, and the like. Further, the semiconductor device thus adopting silicon carbide as its material has characteristics less deteriorated even under a high temperature environment than those of a semiconductor device adopting silicon as its material, advantageously.
Japanese National Patent Publication No. 2000-509559 (Patent Document 1) describes a silicon carbide field effect transistor having a gate trench. The silicon carbide field effect transistor includes: a p region provided near the bottom portion of a gate trench; and a source contact in contact with the p region.